A Skype bug that enables an attacker to bypass the lock screen on several Android mobile devices demonstrates once again the need for additional security to protect corporate data against such flaws, experts say. "Pulser," the developer administrator for XDA-Developers Forum, reported the bug in Skype version 3.2.0.6673, which was released on Monday. Skype is installed on more than 100 million Android devices worldwide, says Microsoft, which acquired the messaging platform in 2011.